Pump



J. M. MCDONNELL 2,862,450

Dec. 2, 1958 PUMP 2 Sheets-Sheet 1 Filed Nov. 2, 1953 H a... m M C y W m I. M m h .J. A m R J Y H B 3 .9 I

Dec. 2, 1958 I J. M. MQDONNELL 2,362,450

PUMP

Filed Nov. 2, 1953 2 Sheets-Sheet 2 I23 ||4 us no n2 "'1'" E I //V V I |2| E us 3; n1

O l I 1 u INVENTOR. b I Joseph M. McDome/l His Attorney PUMP Joseph M. McDonnell, Rochester, N. Y., assignor to Gen- -eral Motors Corporation, Detroit, Mich., a corporation of Delaware Application November 2, 1953, Serial No. 389,798

1 Claim. (Cl. 103-53) This invention pertains to pumps, and particularly to a solenoid type pump and energizing system therefor.

a The majority of present-day motor vehicles employ mechanically actuated, diaphragm type fuel pumps located in the engine compartment, with the suction line connected to an inlet opening located in the fuel tank. As fuel tanks are generally located in the rear portion of the vehicle, some difficulty with this type of fuel system has been encountered, especially in mountainous terrain. I-I'eretofore it has been suggested, as a solution to this problem, to use an electric motor driven fuel pump in the fuel tank. However, due to the fact that D. C. electric motors are subject to sparking at the brushes, elaborate safety systems have to be employed, which render the cost of such units prohibitive. The present invention relates to a solenoid operated pump adapted for mounting within the fuel tank, thereby obviating the problem of sparking, and yet possessing all of the advantages of the electric motor driven unit.

Accordingly, among my objects are the provisions of a solenoid operated fuel pump adapted for immersion in a fuel tank; a further provision of means for energizing the solenoid windings of the pump; and the still further provision of a solenoid pump of extremely low power dissipation.

The aforementioned and other objects are accomplished in the present invention by providing a pump assembly with individual pumping and filling solenoids. Specifically, the preferred pump assembly includes a housing having disposed therein a spring centered piston capable of electromagnetic actuation in either direction. This spring arrangement is such that the springs assist piston movement when the air gaps of electromagnets are a maximum, thereby reducing the power dissipation of the solenoids. The piston divides the housing into a filling chamber and a pumping chamber, the piston being provided with spring-type flapper check and relief valves. The filling chamber is connected through one solenoid plunger to an inlet port, and the pumping chamber is connected through the other solenoid plunger to an outlet port.

In one modified embodiment disclosed herein a single plunger and two solenoids are employed. In still another modified embodiment, a single plunger which tends to center itself within the energized solenoid is employed.

The energizing systems for the solenoids include a flasher mechanism comprising a heated element, which alternately opens and closes a circuit for energizing a relay. The relay has two sets of contacts which are electrically connected to the pumping and filling solenoids, whereby alternate energization of these solenoids may be effected.

Further objects and advantages of the present invention will be apparent from the following description reference being had to the accompanying drawings where'- in a preferred embodiment of the present invention is clearly shown.

In the drawings: Fig. 1 is a schematic diagram of a fuel pump arrangement and energizing means therefor, constructed according to the present invention;

Fig. 2 is a longitudinal, sectional view of the preferred pump construction.

1 Fig. 3 is a sectional view taken along line 33 of Fig. 2.

Fig. 4 is an enlarged view in elevation of the relief valve employed in the pump construction of Fig. 2.

Figs. 5 and 6 are sectional views of modified pump constructions.

With particular reference to Fig. 1, a typical motor vehicle installation of the pump of this invention is diagrammatically illustrated. From an inspection of Fig. 1, it may be seen that the pump 10 is carried by a bracket attached to an exterior wall of a fuel tank 12. The pump 10' is located adjacent the bottom wall of the fuel tank 12 so as to be immersed in the fuel contained therein. The pump 10 includes an intake opening, not shown in Fig. 1, and an outlet opening connected by conduit 13 to the float chamber of a carburetor 14. The bracket 11 includes a pair of spaced terminals 15 and 16 which are connected respectively to the pumping and filling solenoid windings, likewise not shown in Fig. 1'.

With reference to Figs. 2 through 4 the preferredpump construction will be described. The pump includes an outer housing 29 which is through bored and internally threaded at each end for the reception of plugs 21 and 22. The plug 21 has an opening therein constituting an inlet port 23 while the plug 22 has an opening constituting an outlet port 24. An intermediate portion of the housing 20 is provided with an internal annular member which-is fixedly retained in position between a pair of terminals 31 and 32'. The liner 30 constitutes a cylinder for a reciprocable piston in the form of adisc and which is formed 'withan integral axial extending end portion 41 that is attached to a solenoidplunger 43. The piston 40 divides the cylinder, con stituted by liner 30, into a filling chamber and a pumpingchamber 46. The head of piston 40 also has attached thereto a tubular member 42 having a wall opening 42a'which is attached to a second solenoid plunger 44. As seen in Fig. 2 the solenoid plungers 43 and 44 are hollow so as to facilitate the flow 'of fluid therethrough. Moreover, both solenoid plungers are provided with truncated conical end surfaces which cooperate with a pair of spaced magnets 47 and 48 which may be magnetized by solenoid windings 33' and 34, respectively. The magnet assemblies 47 and 48 are likewise formed with truncated conical pole faces so that an annular air gap is formed between each magnet assembly and each solenoid plunger. One end of solenoid winding 33 is connected to the terminal 31 while one end of solenoid winding 34 is connected to the terminal' 32. The terminals 31 and 32' correspond to terminals 15 and 16 shown in Fig. l. The other ends of coil 33 and coil 34 are grounded by soldering to sleeves 33a and 34a.

The solenoid windings 33 and 34 are confined between magnet assemblies 47 and 48 and annular members 35 and 36, respectively. Annular member 35 has associated therewith a cupshaped member 37 which supports a screen type filter element 39, that prevents the passage of foreign matter from the fuel tank through the pump to the carburetor. The cup shaped member 37 I is provided with a central opening and a depression in which is supported a spring 51-. The plug member 22 is likewise provided with a recess in which is supported a spring 52. The springs 51 and 52 normally engage the ends of plungers 43 and 44 so as to dampen the shock when either plunger seats against magnets 47 or 48. The plug 22 is also provided with a check valve assembly which prevents the reverse flow of fluid from the carburetor to the fuel tank. The check valve assembly comprises a disc 38 normally urged upon an annular shoulder by means of a spring 54. It may also be seen that the rod 41 is provided with a longitudinal groove 53 through which the inlet port 23 must communicate with the chamber 45.

With particular reference to Figs. 3 and 4 the construction of the piston of the assembly will be described.

Piston '40 is provided with four openings spaced at 90 flapper valve 65 as shown in Fig. 4. The valve 65 constitutes a relief valve which prevents the existence of excessive pressures in the pump chamber 46. The valve 65 is carried on the rod end surface of the piston 40 by means of a rivet 64. The openings 60, 61 and 62 cooperate with a spring type flapper valve 70 having 3 radiating arms 66, 67 and 68. The flapper valve 70 constitutes a check valve permitting the flow of fuel from the chamber 45 to the pumping chamber 46, and is mounted on the head surface of the piston 40 by a screw 71.

Referring again to Fig. 1, the energizing circuit will be described. The energizing circuit comprehends the use of a battery 80, one terminal of which is connected to ground by a wire 81, and the other terminal of which is connected through the ignition switch 82.to a wire 83. Wire 83 is connected by wire 84 to a pilot light 86 which is connected in series with a wire 85. The wire 85. is connected to one end of an element 89 as well as oneend of a heating coil 87. The element 89 determines the position of a pivotally mounted contact arm 88. which is biased in a clockwise direction by a spring 89a. LThe contact arm 88 carries a contact 90 adapted for engagement with a contact 91 having connection with the other end of heating coil 87 and a relay coil 92. The other end of relay coil 92 is connected to ground. Wire 83 is also connected to a wire 93 which connects with a contact arm 94 of the relay 95. The contact arm 94 car- Iies contacts 96 and 97, contact 96 being the filling solenoid contact and contact 97 being the pumping contact. Contact 96 is adapted to engage the contact 98 connected by wire 99 to the filling solenoid terminal 15, while contact 97 is adapted to engage a contact 100 connected by wire 101 to the terminal 16 on pump.

Operation of the pump and energizing circuit is as follows. When ignition switch 82 is closed, heating coil resistor 87 will be connected through the winding 92 across the battery 89. Inasmuch as the ohmic value of resistor 87 is substantial as compared to the ohmic value of relay winding 92, insufficient current will flow through the relay winding to actuate contact arm 94. Accordingly, the pumping solenoid 33 will be energized thereby moving the piston 40 to the right as viewed in Fig. 2, drawing fuel from tank 12 into the chamber 45 while at the same time forcing fluid from the chamber.

46 through the check valve 38 to the outlet port 24.

After a predetermined interval has elapsed, the heating effect of resistance 87 will cause the element 89 to elongate, the element 89 being constituted by a wire, so as to close contacts 90 and 91. The closure of contacts '90 and 91 will short out the resistance 87 thereby'enerchamber 45 will pass through the check valve 70 into the chamber 46. The flasher unit shown in Fig. 1,

4 may be of such a character as to effect approximately to 150 cycles of energization per minute.

With reference to Figs. 5 and 6, two modified versions of a pump construction adapted for use with the flasher unit of Fig. 1, will be described. The pump shown in Fig. 5 includes a housing having disposed therein a single plunger 1111 which is attached to a piston 111. The pump assembly of Fig. 5 likewise includes a pumping solenoid 112 and a filling'solenoid 113. However, the pumping cylinder 114 includes only a single chamber 115, which is connected through port 116 and a check valve 117 to an inlet opening 118. The chamber is likewise connected to a check valve 119 to an outlet port 120. During reciprocation of the piston due to intermittent andalternate energization of solenoids 112 and 113, fluid will be taken from inlet port 118 and through outlet port 120. In the embodiment of Fig. 1, the piston 111 is provided with a single opening 121 which is normally covered by spring type relief valve 122 similar to that described in Fig. 4. Thespring 123 acts as a cushion when plunger 119 seats in magnet 124.

With reference to Fig. 6, a still further modified pump assembly is disclosed. The pump still includes a pumping solenoid 136 and a filling solenoid 131. In this instance the solenoid plunger 132 constitutes the pumping element and is reciprocable in a tubular member 133, and normally centered therein by a pair of opposed springs 134 and 135. The pump includes a chamber 136 having connection through a check valve 137 to an intake conduit 141. The chamber 136 is also connected through a check valve 138 to an outlet conduit 139. The chamber 136 is also provided with a pressure relief valve 140 which may be of the spring flapper type as shown in the previous embodiments. When either of the solenoid coils -131 is energized, plunger 132 tends to center itself within the energized coil. Thus, when solenoid coil 130 is energized the plunger will assume the position shown in Fig. 6, at which time fluid will be forced from chamber through the check valve 138 through the conduit 139. Conversely, When solenoid coil 131 is energized the plunger 132 will center itself Within this coil thereby driving fluid into chamber 136 through a valve chamber 137 from the conduit 141.

From the foregoing it is apparent that the present invention' provides an electromagnetic pump adapted for immersion in the fuel tank of a motor vehicle. More. over, the present invention provides an improved system for the winding of the pump to assure an adequate supply of fuel to the float chamber of a carburetor. 'Moreover, the embodiments of this invention possess all the attributes of the electric motor driven pumps, and yet obviate the possibility of explosion due to an electrical discharge within the fuel tank.

While the embodiments of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

A pump having an elongated casing adapted to be immersed in a liquid fuel, a pair of solenoid coils coaxially fixed within said casing, a pair of magnets between said coils and cooperating with said casing in defining an operating cylinder, a piston in the form of a disc located in said cylinder and dividing the latter into a filling chamber and a pumping chamber, two plungers forming a unit with said piston, one of said plungers being slidable within each of said coils, one-way valve means carried by said piston, spring means abutting the ends of said unit and urging the latter toward a medial position, an inlet passage for said liquid fuel extending into one end of said casing and through one of said plungers to saidfilling chamber, an outlet passage for said liquid fuel extending from said pumping chamber through the other of said plungers and from said casing, one-way valve means in said outlet passage, and said solenoid coils being adapted to be energized alternately to effect pumping action through said inlet and outlet passages.

References Cited in the file of this patent UNITED STATES PATENTS 5 Van Depoele July 1, 1890 Carpenter May 8, 1894 Smith Feb. 22, 1910 Kopf Aug. 3, 1915 10 Kocourek Feb. 26, 1918 6 Wright Nov. 8, 1921 Ruckelshaus Mar. 22, 1923 Tice Nov. 22, 1932 Freeman July 2, 1935 Winckler Oct. 22, 1935 Replogle Sept. 15, 1936 Mesh Sept. 25, 1951 Reutter Oct. 25, 1955 FOREIGN PATENTS Germany July 6, 1933 

